1 | US DOE Geothermal Program eere.energy.gov
Geothermal Technologies Program 2010 Peer Review
Multiparameter Fiber Optic Sensing System for Monitoring Enhanced Geothermal Systems
Dr. Aaron J. Knobloch, PIGE Global Research
High Temperature Tools and Sensors,Downhole Pumps and Drilling
May 19, 2010
This presentation does not contain any proprietary confidential, or otherwise restricted information.
2 | US DOE Geothermal Program eere.energy.gov
• Timeline – Project Start: 3/30/2010 Project End: 3/30/2012– Progress: 5%
• Budget – Total DoE Share: $2,085,062 Total Cost Share: $567,689– Total Program Size: $2,652,751– FY10 $1.0M-1.2M
• Barriers – High Temperature Measurement Tools & Sensors– Well Construction (C)– Site/Well Characterization (D)– Reservoir Validation (I)– Reservoir Scale-up (L)– Reservoir Sustainability (M)
• Partners– GE Global Research (Lead)– Qorex LLC– GE Sensing– AFL Telecommunications– Sandia National Labs
Project Overview
3 | US DOE Geothermal Program eere.energy.gov
Project Overview
4 | US DOE Geothermal Program eere.energy.gov
Project Relevance & Impact
Project Objectives
• Demonstrate reliability of fiber and distributed temperature, strain and vibration sensing sub-systems for EGS at 374ºC and 220 bar in the presence of hydrogen.
• Develop a high accuracy point pressure gauge and distributed pressure sensor to meet EGS requirements.
• Integrate multiple sensor sub-systems into a single field-ready cable and system.
• Plan for field deployment tests of this technology.
5 | US DOE Geothermal Program eere.energy.gov
Project Relevance & Impact
Impact on Geothermal Energy Development
• Development of real-time, reliable sensors for distributed, multiparameter sensing of the geothermal asset
• Enable fracture system model development and validation during site characterization
• Measurements of thermal drawdown, water injection, and recovery during productionThe effects of injection into the stimulation well
are clearly seen when using DTS to monitor the recovery well to 1km deep
6 | US DOE Geothermal Program eere.energy.gov
Technical Approach
7 | US DOE Geothermal Program eere.energy.gov
Sensor Reliability
Two Key Risks are Being Mitigated:• Hydrogen Darkening
– Pure Silica Core Fibers– Reliability analysis examining mechanical and loss
characteristics at high temperature
• Mechanical Reliability– Fiber coatings robustness to corrosion– Cable design – metal fatigue models of Armor
8 | US DOE Geothermal Program eere.energy.gov
Analysis of Commercially Available Systems
• Raman DTS– Established, simple measurement system– Wavelength dependent differenital fiber attenuation
• Brillouin DTSS– Less mature, more complex approach to temperature & strain
measurement– Single ended architecture that may be less sensitive to H2
ingress
• Coherent Rayleigh Backscatter– Acoustic method for measuring vibration of a fiber– Early stages of development and needs evaluation
9 | US DOE Geothermal Program eere.energy.gov
Innovative Sensor & Cable Development
• Multiparameter Sensor – Brillouin DTSS – Adaptation to single core– Fiber Bragg Grating sensors & packaging
• High Accuracy Point Pressure– Based on GE product with accuracy of 0.001% and stability of
100ppm/year– Optical interrogation and die design for 375ºC and 220 bar
application
• Cable Design– Leverage experience in SAGD applications– Ability to withstand thermal expansion without imparting strain to
the fiber– Fiber splice & cable spooling processes development
10 | US DOE Geothermal Program eere.energy.gov
Project Plan
11 | US DOE Geothermal Program eere.energy.gov
Project Timeline
12 | US DOE Geothermal Program eere.energy.gov
Project Spend Plan
13 | US DOE Geothermal Program eere.energy.gov
• This effort brings together currently available technology with new sensors and packaging to develop key hardware necessary for well characterization, validation, and sustainability
• Key risks to the development of advanced optical sensors for geothermal systems will be mitigated– Hydrogen darkening of optical fiber– Mechanical design of package including armored cable– Integration of multiple measurands and measuring techniques
into a single sensor system
Project Summary
14 | US DOE Geothermal Program eere.energy.gov
Future Directions
• Key Outcomes– Ability to log real-time geothermal asset performance– Integration of multiple parameters in a single sensing
systems– Understanding of the reliability and failure modes of current
systems
• Specific Goals, milestones and decision points – See earlier planning and timeline slides
15 | US DOE Geothermal Program eere.energy.gov
Supplemental Slides